KR102245011B1 - Method and device for determining a concentration of an analyte in a bodily fluid - Google Patents

Abstract

A method, an analysis device 114, and an analysis system 110 for determining the concentration of at least one analyte in body fluid 112 are disclosed. The method comprises the steps of: a) applying a sample of bodily fluid 112 to a test carrier 116; b) illuminating the test carrier 116 by using at least one light source 127; c) receiving the light carried by the test carrier 116 by using at least one detector 132; d) determining the concentration of the analyte by evaluating at least one detector signal generated by detector 132. At least one light source 127 is modulated by using at least two modulation frequencies. The detector signal is demodulated with at least two modulation frequencies to produce at least two demodulated detector signals, each demodulated detector signal corresponding to one of the modulation frequencies. The method includes error detection based on a comparison of at least two demodulated detector signals.

Description

Method and device for determining the concentration of an analyte in body fluids

The present invention discloses a method, an assay device, and an assay system for determining the concentration of at least one analyte in a bodily fluid. The methods, systems, and uses according to the invention may be specifically used to determine the concentration of glucose in one or more body fluids, such as in whole blood. However, additionally or alternatively, one or more other types of analytes and/or one or more other types of body fluids may be used. The invention may also be applied in the field of diabetes management, both in home monitoring and in hospital applications. Additionally or alternatively, other uses are feasible.

In the art, a large number of device methods are known for determining the concentration of one or more analytes in bodily fluids. Without limiting the scope of the present invention, in the following reference is made primarily to the determination of glucose as an exemplary and preferred analyte.

등의 문헌 ("The Technology Behind Glucose Meters: Test Strips", Diabetes Technology & Therapeutics, Vol. 10, supplement 1, 2008, S-10 내지 S-26) 에 대해 참조가 행해질 수 있다. 다른 타입들의 테스트 엘리먼트들 및/또는 테스트 물질들이 실현가능하고 본 발명 내에서 이용될 수도 있다.Determination of the concentration of one or more analytes in body fluid may specifically be performed by using photometric measurements. A sample of bodily fluid may be applied onto a test carrier illuminated by light to perform photometric measurements. Typically, reflection measurements are performed to determine the amount of light that is elastically or inelasticly reflected, scattered, or restricted by the test carrier. The test carrier is typically one or more chemical compounds equipped for carrying out a detectable reaction, which is replaced by the use of at least one test chemical, i.e. a detectable change of the test carrier, in particular an optical change such as a color change, or It is based on the use of chemical mixtures. Test chemicals are often also referred to as test substances, test chemistry, test reagents, or detector substances. For details of potential test chemicals and test elements containing such test chemicals, which may also be used within the present invention, see J.

Reference may be made to “The Technology Behind Glucose Meters: Test Strips”, Diabetes Technology & Therapeutics, Vol. 10, supplement 1, 2008, S-10 to S-26, et al. Other types of test elements and/or test materials are feasible and may be used within the present invention.

By using one or more test chemicals, a detection reaction may be undertaken, and the course of the detection reaction is dependent on the concentration of analyte to be determined. Typically, as may also be the case with the present invention, the test chemical is provided to perform at least one detection reaction when the analyte is present in a body fluid, where detection reactions such as kinetics of detection reactions The limit and/or degree of is dependent on the concentration of the analyte. In the case of photometric measurements, the test carrier may be illuminated with light, where the light may be reflected from the test carrier in a diffuse manner or may be detected by the analysis device. For example, the concentration of the analyte in the sample can be determined by measuring the reflectivity of the test carrier when the detection reaction is complete. Additionally or alternatively, the progress of the detection reaction may be monitored by measuring the temporal change in reflectance. Accordingly, in photometric measurements, the test chemical may preferably be provided to change at least one reflective property, preferably color, due to a detection reaction.

Measurement and analysis of the returned light typically imposes some technical challenges. On the one hand, these measurements typically involve small currents and/or voltages. However, the measurement of these small currents or voltages is a challenge, since interferences such as interferences due to low frequency voltages may occur. On the other hand, optical disturbances may occur due to ambient light. Accordingly, for the determination of the concentration of an analyte in a sample by photometric measurements, analysis devices and methods become necessary to reduce the inference of these disturbances.

In EP 0 632 262 B1, a method for detecting and evaluating analog luminosity signals in a test carrier analysis device is proposed. The test field of the test carrier is illuminated by a light source clocked in the light and dark phases. The light and dark phases form an irregular sequence with a frequency spectrum having a large number of different frequencies. The light is reflected and detected by the measuring receiver, and the measured value is passed to the measurement integration and digitization circuit for evaluation, where the irregular signal is filtered out.

In EP 1 912 058 B1 a system equipped for measuring and evaluating optical signals for detecting an analyte in an analyte liquid is described. The system includes a test carrier and a light source for illuminating the optical evaluation area of the test carrier. Additionally, the system includes two signal sources provided for generating two control signals mixed by the mixer unit to generate a light control signal for the light source. The optical sensor receives the conveyed light and converts it into a measurement signal. In addition, the system includes two frequency-selective amplifiers, each receiving one of a measurement signal and a control signal, and an evaluation unit to which the output signals of the frequency-selective amplifiers are supplied. In the evaluation unit, these output signals are compared, and information on the interference of the measurement by external light is determined from the result of the comparison. If the interference of a measurement beyond a certain threshold is determined, the measurement is considered to be in error. Measurements are rejected and glucose concentration values are not issued.

Also, in many cases, the test carrier must be oriented within the device to determine the concentration of one or more analytes, so that the device can perform the determination of the concentration. In US 2003/169426 A1, a test meter is described which is capable of determining the orientation of a test member therein. The test member has a first major surface and an opposing second major surface. Each major surface comprises an orientation indicator region, and the orientation indicator regions differ by at least one optical property, eg reflectance. The test instrument has a test area to receive the test member and to contain the optical orientation sensor. The optical orientation sensor generates an orientation signal indicating optical properties of the orientation indicator region.

In US 5 526 120 A, a test strip and apparatus each having asymmetry is proposed. The asymmetries are synthesized, allowing the test strip to be inserted into the device when the test strip is correctly aligned, but prevents the test strip from being fully inserted when the test strip is upside down. The device detects whether the strip is fully inserted or not.

Despite the advantages implied by these devices and methods known in the art, still, a large number of technical challenges remain. Thus, as an example, many devices and methods known in the art are not suitable for recognizing disturbances prior to or during measurement. As an example, these disturbances may result from internal disturbances such as fluctuations of one or more light sources and/or noise in electronic components of the devices. In addition, external disturbances such as disturbances induced by ambient light must be considered. These disturbances may lead to significant defects and falsesification of measurement results. However, typical methods and devices known in the art only allow error detection at the end of each measurement. For example, in paragraph [0047] of EP 1 912 058 B1, it is disclosed to compare the analysis results that were determined not directly from the raw data, but from the raw data of the output signals of the frequency-selective amplifier. Thus, if the measurement is rejected, the entire test carrier soaked by the sample is rejected and a new sample has to be applied on the new test carrier, which implies that a new sample has to be taken from the patient or user. Thus, in general, known methods and devices typically imply the drawback that test carriers are wasted, and the user or patient, at least to some extent, will have to repeatedly generate a sample of bodily fluid in order to obtain a reliable measurement. do. Further, specifically, taking into account the increased use of state-of-the-art light sources such as energy-saving lamps, LEDs, and the like, and taking into account the increased trend towards miniaturization of analysis devices, disturbances in photometric measurements may increase. As a result, there is a strong need for suitable methods and devices to at least partially avoid waste of test carriers and frequent generation of samples by still providing fast and reliable measurement results.

Further, EP 1 912 058 B1 discloses that the first signal source generates a first control signal having a fundamental frequency and the second signal source generates a second control signal having a frequency that is a multiple of the fundamental frequency. Intensities of the first control signal and the second control signal are different from each other. However, the use of control signals with different intensities may increase the likelihood of erroneous error detection in the case of low measurement signals, due to identifying low measurement signals as errors and not detecting disturbances. Accordingly, even if a valid measurement signal is measured, a valid measurement signal may be erroneously identified as a disturbance rather than a valid measurement signal.

Therefore, it is an object of the present invention to provide methods and devices for determining the concentration of an analyte in a body fluid, which overcomes the above mentioned drawbacks and problems of known methods and devices. Advantageously, methods and devices will be disclosed that can reliably determine the concentration of an analyte in a bodily fluid even in the presence of disturbances.

This problem is solved by a method, an analysis device, and an analysis system for determining the concentration of at least one analyte in a bodily fluid, along with the features of the independent claims. Certain embodiments that may be realized in an isolated manner or in any arbitrary combination are listed in the dependent claims.

As used in the following, the terms "have", "comprise" or "include" or any arbitrary grammatical variations thereof are in a non-exclusive manner. Is used. Accordingly, these terms refer to both a situation in which, in addition to the feature introduced by these terms, no additional features exist in the entity described in this context, and a situation in which one or more additional features exist. You may. As an example, the expressions "A has B", "A comprises B" and "A includes B", in addition to B , A situation where no other element exists in A (i.e. a situation where a consists entirely and exclusively of B) and, in addition to B, one or more additions, such as element C, elements C and D, or even additional elements The elements of may refer to both of the situations that exist in entity A.

In a first aspect of the invention, a method for determining the concentration of at least one analyte in a body fluid is disclosed.

Body fluids are generally any type of body fluid, preferably blood, preferably whole blood; Interstitial fluid; Urine; It may be a group consisting of saliva, or may be selected from it. Additionally or alternatively, other types of body fluids may be used. Additionally or alternatively, further processed bodily fluids such as blood plasma or blood serum may also be used.

The analyte may generally be a substance, compound, or combination of substances or compounds that may be present in body fluids. The analyte may be part of the metabolism of human or animal life, or may be a substance that may participate in the metabolism. Specifically, the analyte may be a metabolite. Preferably, the analyte is glucose, lactate, triglycerides, ketone, ethanol, total cholesterol, HDL cholesterol, LDL cholesterol, urea, uric acid. ), creatinine, GOT, GPT, GGT, ammonia. Additionally or alternatively, also other clinical chemical parameters, or alkaline phosphatase (ALP), creatine kinase (CK), amylase, pancraetic amylase, (gamma)-glutamyltransferase ((Gamma)-Glutamyltransferase; GGT), Glutamic-oxaloacetic transaminase (GOT), Glutamic-pyruvic transaminase (GPT), bilirubin (bilirubin), hemoglobin hemoglobin) and potassium. Additionally or alternatively, the analytes may be substances or combinations of substances involved in the intrinsic and/or extrinsic coagulation pathway. In general, an analyte may be a clinical parameter of any type of bodily fluid that may be of interest for clinical purposes, such as any type of clinical parameter that may be determined from whole blood. Without limiting further embodiments of the invention, in the following, reference will be made to the detection of glucose in whole blood, in most parts.

The method comprises method steps as given in claim 1 and as listed as follows. The method steps may be performed in a predetermined order, that is, in the order a)-b)-c)-d). However, other orders of method steps are feasible, such as b)-a)-c)-d). Also, for example, by performing at least partially concurrently with method steps a) and b), and/or by performing at least partially simultaneously with method steps b), c), and d), one or more of the method steps may be It may be performed in parallel and/or in a timely overlapping manner. Further, one or more of the method steps may be performed repeatedly. Thus, as an example, method steps b) and/or c) are performed at least once before method step a), and method steps b) and/or c) after performing method step a). By performing at least once, method steps b) and/or c) may be performed repeatedly. In addition, there may be additional method steps not listed.

The method steps are as follows:

a) applying a sample of bodily fluid to a test carrier;

b) illuminating the test carrier by using at least one light source;

c) receiving the light carried by the test carrier by using at least one detector;

d) determining the concentration of the analyte by evaluating at least one detector signal generated by the detector.

Here, at least one light source is modulated by using at least two modulation frequencies. The detector signal is demodulated with at least two modulation frequencies to produce at least two demodulated detector signals, each demodulated detector signal corresponding to one of the modulation frequencies. The method further includes error detection based on a comparison of the at least two demodulated detector signals.

As used herein, application of a sample of bodily fluid to a test carrier generally refers to the step of bringing the test carrier into contact with the sample of bodily fluid in any technically feasible manner. For example, by applying the sample to at least one application location, application may occur manually or automatically. The sample may be applied to a test chemical in a test carrier, such as a test field containing at least one test chemical. Additionally or alternatively, the sample may be applied to a different application location, such as an opening in a capillary element provided to transport the sample to the test chemical by capillary forces. Application of a sample of bodily fluid to the test carrier may occur prior to, during, or after insertion of the test carrier into a container of an assay device equipped to perform the method. In general, means and devices for applying a sample to a test carrier are known to those skilled in the art.

In general, as before method steps a) to d), further method steps may be carried out, for example before application of a sample of bodily fluid to a test carrier as suggested in method step a). Further, in some embodiments, additional method steps may be performed even without using a test carrier. Accordingly, as outlined in more detail below, prior to carrying out the method steps a) to d), the ambient light error detection step and/or the determination of a dry empty value and/or It may be possible to perform a location verification step. Accordingly, the optional ambient light error detection step indicates that the ambient light does not allow analyte measurement (such as when the ambient light level at at least some modulation frequencies must exceed the tolerance threshold). If necessary, the measurement may be interrupted without the sample application being carried out later. Similarly, additionally or alternatively, if the determination of at least one dry empty value is to be reached in the conclusion that the test carrier is unavailable, for example due to aging or deterioration effects, sample application is not carried out later Therefore, the measurement may be interrupted. Similarly, additionally or alternatively, if the position verification step is to indicate that the test carrier is misplaced or not properly aligned, the measurement may be stopped without subsequent sample application.

As used herein, the term test carrier generally refers to a test element provided to determine the concentration of at least one analyte in a bodily fluid. Specifically, the test carrier may be an optical test carrier provided to optically determine the concentration of an analyte. The test carrier may generally have any technically feasible format. The test carrier may contain one or more test chemicals that may be in direct or indirect contact with bodily fluids. For potential embodiments of at least one test chemical, reference may be made to the disclosure of potential test chemicals given above or given in more detail below. Specifically, the test carrier may include one or more test fields having one or more continuous or discontinuous detection layers comprising at least one test chemical. Additionally, such as one or more reflective layers having one or more colored pigments such as white pigments, and/or one or more separating layers provided to separate one or more components of a body fluid, such as one or more cellular components There may be one or more additional layers. Other embodiments are feasible. The test carrier may generally have an arbitrary shape or format, such as one or more of the test carrier formats known in the art. As an example, the test carrier may be selected from the group consisting of a test strip, a test tape, a test disk, and an integrated test carrier having at least one test chemical and at least one lancet element.

The test carrier may include at least one substrate and at least one test chemical applied directly or indirectly to the substrate. The test chemical may be provided to perform at least one detection reaction in the presence of at least one analyte to be detected, and to change at least one optically detectable property due to the detection reaction. For potential embodiments of the test chemical, reference may be made to the prior art documents cited above and/or to other embodiments given in more detail below. Specifically, the test chemical may include one or more enzymes adapted to perform an enzymatic reaction in the presence of an analyte to be detected. In addition, the test chemicals include colorants or dyes; Mediator; It may also contain one or more of co-enzymes. Other embodiments are feasible. The test chemical may be tracked by monitoring the kinetics of the detection reaction by monitoring at least one optically detectable property, such as one or more of color, remission, reflection, fluorescence, and phosphorescence. It may be provided so as to be. Thus, as an example, the test carrier makes at least one optical measurement directly, e.g., through an opening in the substrate, through a window in the substrate, and/or by inspecting the test field at least a portion of the test chemical. It may also be provided to be accessible for use.

As used herein, the substrate may generally be an optionally formed element that can be used as a carrier for additional elements. As an example, the shape of the substrate may be selected from the group consisting of a strip, a tape, and a disk. Various embodiments are generally feasible.

The substrate may comprise a single layer setup or may comprise a multilayer setup. Accordingly, the substrate may comprise one or more of a paper material, a plastic material, preferably a foil, a metal, and a ceramic material. Also, combinations of materials are feasible. The substrate may comprise a multi-layer setup, for example by using a laminate. Additionally, the substrate may include one or more fluid structures. For this purpose, two or more substrates may be provided, wherein a channel is arranged between the substrates, for example by separating the substrate by one or more spacers. Additionally or alternatively, one or more fluid structures on the surface of the substrate may be provided by using one or more open capillary channels, such as, for example, one or more capillary slits. Various embodiments are feasible and are generally known in the art.

As outlined above, the test carrier may comprise at least one test field applied directly or indirectly to the substrate, as applied to the surface of the substrate and/or incorporated within the substrate, wherein the test The field contains at least one test chemical. Here, one single test field having at least one test chemistry may be applied, and/or a plurality of test fields having the same test chemistry and/or different types of test chemistry may be used.

The test carrier may include at least one application location to which a sample of bodily fluid may be applied. Consequently, the at least one application location may be a location in which a sample of bodily fluid can be applied to the test carrier. In general, the test carrier may contain a plurality of application locations.

As outlined above, the at least one test chemical preferably forms at least one test field and/or is part of at least one test field. The test field may contain a monolayer setup that includes only one detection layer containing the test chemical. Alternatively, the test field may have a multilayer setup of at least two layers, wherein at least one detection layer comprising at least one test chemical is one or more diffusion layers, and/or one or more separation layers, and /Or may be combined with one or more additional layers, such as one or more layers of pigment to provide an optical background, such as a white background, for improved optical measurements. Multilayer setups of this type are known in the art. Thus, as an example, the test field may have at least one detection layer and, additionally, at least one separation layer (eg, for separating blood cells) and/or one or more metal oxides, preferably , An optical layer comprising one or more pigments such as one or more inorganic pigments such as titanium dioxide.

For details of potential test chemicals that may also be used within the present invention, see The Technology Behind Glucose Meters: Test Strips, Diabetes Technology & Therapeutics, Vol. 10, Supplement 1, 2008 by J. Hoenes et al. , S-10 to S-26). Further, reference may be made to WO 2010/094426 A1 and WO 2010/094427 A1. Additionally or alternatively, test substances as disclosed in WO 2007/012494 A1, WO 2009/103540 A1, WO 2011/012269 A2, WO 2011/012270 A1, or WO 2011/012271 A2, also referred to as cNAD test substances This may be named. Further, reference may be made to EP 0 354 441 A2, EP 0 431 456 A1, EP 0 302 287 A2, EP 0 547 710 A2, or EP 1 593 434 A2. The test materials disclosed in all these documents may also be used within the present invention. Other types of test elements and/or test materials are feasible and may be used within the present invention.

The light source as used in method step b) may generally be or may comprise one or more optional light sources provided to illuminate the test carrier. As used herein, “light” generally refers to electromagnetic waves in one or more of the visible, ultraviolet, and infrared spectral ranges. Here, the visible light spectral range generally refers to a spectral range of 380 nm to 780 nm. The infrared spectral range generally refers to a spectral range of 780 nm to 1 mm, preferably 780 nm to 3.0 μm. The ultraviolet spectral range generally refers to a spectral range of 1 nm to 380 nm, preferably a spectral range of 50 nm to 380 nm, and more preferably a spectral range of 200 nm to 380 nm. Most preferably, the light source is provided to emit light in the visible spectrum range.

For example, the light source may be a pulsed light source, such as a light-emitting diode (LED); A laser, preferably a laser diode; Incandescent light source; It may be a light source selected from the group of light bulbs. Additionally or alternatively, several light sources may be used, for example at least two light sources having different emission wavelengths and/or having different spectral properties.

As used herein, the term conveyed light as used in method step c) is generally, by means of a test carrier, specifically by means of a test optic, and more specifically, by at least a test chemical. Refers to the light reflected by one test field. Reflection can also occur in a diffuse manner. In general, the reflection may be wholly or partially resilient and/or inelastic. In some embodiments, method step c) is performed such that the angle of incidence of the illumination in method step b) is different from the angle of inspection in method step c), such that direct reflection of light is at least partially excluded. do. The conveyance measurement as used in method steps b) and c) may be performed by illuminating the test carrier and/or a portion thereof, and by measuring the reflected and/or scattered light from the test carrier. By performing this measurement, color changes in the test chemical on the test carrier, which may occur due to the progress of the detection reaction, may be detected. As a result of the measurement in method step c), a carrier signal such as a relative carrier may be generated, as outlined in more detail below, and as is generally known in the field of optical detection.

The conveyed light or a portion thereof may be received by at least one detector. The detector may be any detector configured to receive light and convert the light into one or more electrical or electronic signals. The detector may include at least one light-sensitive element for detecting light propagating from the test carrier to the detector. The detector may generate one or more output detector signals, in particular at least one electronic signal, which may be further evaluated. The detector signal may generally be or may include an analog signal and/or a digital signal. Specifically, the detector signal may include a current signal and/or a voltage signal. For example, by providing a continuous detector signal comprising continuously generated detector signals and/or detector signals generated at predetermined time points and/or with a predetermined detection frequency, the at least one detector signal is a single detector signal. It may or may contain multiple detectors signals. The at least one detector signal may be used directly or indirectly in method step d). Accordingly, the detector signal may be directly processed to determine the concentration of the analyte. Additionally or alternatively, the detector signal as provided by the detector, also referred to as the raw detector signal or the primary detector signal, is converted to one or more secondary detector signals, e.g., by applying one or more of a filtering and/or averaging process. To convert to, one or more preprocessing steps may be applied to the detector signal. In the following, when referring to a detector signal, both an option of using one or more primary detector signals and an option of using one or more secondary detector signals will be implied.

Generally, in some embodiments, the detector comprises a photodiode; Photomultiplier; It may comprise at least one light-sensing element selected from the group consisting of an imaging detector, in particular a camera chip such as a CMOS and/or CCD chip. Other light-sensitive elements are feasible.

In method step d), the concentration of the analyte is determined by evaluating at least one detector signal generated by the detector. As outlined in more detail below, specifically, by using at least one evaluation algorithm, in some embodiments, by using at least one data processing device equipped to automatically perform the evaluation algorithm, For example, evaluation may be performed automatically by using at least one software program.

At least one light source is modulated by using at least two modulation frequencies. As used herein, the modulation of light may specifically be or imply a periodic change of at least one parameter of light, such as at least one parameter selected from the group consisting of amplitude, frequency, and phase. As further used herein, the modulation frequency of the modulation is the frequency of the periodic change of at least one parameter. Thus, mathematically speaking, the modulation may be the multiplication of the parameter to be modulated with a periodic function such as one or more of the following functions:

는 변조의 위상을 나타낸다. 추가적으로 또는 대안적으로, 변조되어야 할 파라미터는 주기적 델타 함수와 승산될 수도 있고, 및/또는 직사각형 함수와 같은 주기적 펄스 함수와 승산될 수도 있다. 다른 타입들의 변조가 실현가능하다.Where a represents the amplitude of the modulation, where f represents the frequency of the modulation, where

Represents the phase of the modulation. Additionally or alternatively, the parameter to be modulated may be multiplied with a periodic delta function and/or may be multiplied with a periodic pulse function such as a rectangular function. Other types of modulation are feasible.

Modulation with at least two modulation frequencies, such as f1 and f2, generally refers to a repeated modulation with twice the above-mentioned multiplication, i.

The frequencies and/or the number of possible detection channels operating in parallel may be limited by processing power, such as installed processing power, and/or by the energy required for mathematical calculation and processing. For example, for a battery-powered analysis device such as a battery-powered handheld meter, three frequencies per light source may be used. However, for example, for analysis devices connected to an external energy source, embodiments with more frequencies are feasible.

As further used herein, demodulation generally refers to an inverse process compared to modulation. Thus, as an example, demodulation may imply multiplying or mixing the modulated function with a periodic function having a specific frequency, also referred to as the modulation frequency. Further, demodulation may imply filtering or suppressing high frequency components after performing multiplication and/or mixing to obtain low frequency components. For the first process, an electronic mixer or multiplier that multiplies the signal to be demodulated by at least one demodulation frequency may be used, and for the latter process, a low-pass filter may be used. Thus, in general, demodulation may imply a shifting or change of the signal from the original frequency of the optical signal to a frequency that is evaluable and analyzeable for error detection. At least one light source may be modulated and/or demodulated by using two or more modulation frequencies.

Modulation frequencies may originate from a signal source that may generate two or more control signals having two or more different frequencies that may be used as modulation frequencies for modulation and/or demodulation. As an example, the same signal source may be used to generate modulation frequencies for both modulation and demodulation. In general, modulation frequencies for modulation may be the same as modulation frequencies of demodulation. In general, the signal source is, for example, a sinusoidal signal; Rectangular signal; Trapezoidal signal; It may be a signal generator that generates a delta signal, preferably a signal selected from the group of periodic delta signals. In the optional mixer unit, one control signal for controlling the pulsed light source may be generated by mixing these two control signals. The test carrier may be illuminated by this modulated light signal.

The control signals may have the same strength. As used herein, the term “intensity” refers to the intensity level and/or amplitude level of a signal. The strength of the control signals may be equal to the strength of the detector signal. Accordingly, the probability of erroneous error detection in the case of low detector signals may be reduced.

The at least one light source is at least one first light source modulated by at least two modulation frequencies and at least one at least one modulated by at least two modulation frequencies different from at least two modulation frequencies that cause the first light source to be modulated. It may also include a second light source. Accordingly, in this embodiment, it may be possible to illuminate the track carrier by means of two light sources. This may be an advantage, as it may be possible to illuminate two different locations on the tracking carrier indicating the determination of the two measurement values.

In general, when using more than one light source, it may be possible to illuminate one, two or more different locations. Accordingly, at least one first light source may be provided to illuminate at least one first position, and at least one second light source may be provided to illuminate at least one second position, where at least one The first position and the at least one second position may be wholly or partially identical or may not be wholly or partially identical, such as being spatially separated and/or overlapping. For example, these different locations may be located on the same test carrier and/or may be located on different tracking carriers. Accordingly, it may be possible to illuminate two or more locations on two or more different test carriers, and thus determine two or more measurement values of two or more different test carriers with the same device. Different test carriers may have different configurations and/or different luminous intensity properties, such as different geometries.

The detector signal is demodulated with at least two modulation frequencies to produce at least two demodulated detector signals, each demodulated detector signal corresponding to one of the modulation frequencies.

The process of demodulation can be understood as extracting demodulated optical signals from detector signals. In the above-mentioned embodiment in which two light sources each modulated by two modulation frequencies may be used, at least two demodulated detector signals may be generated for the modulation frequencies that cause the first light source to be modulated. And, for modulation frequencies that cause the second light source to be modulated, at least two demodulated detector signals may be generated.

Demodulation may include independently multiplying the detector signal by the modulation frequencies and filtering the results by using low-pass filters. A low-pass filter may be understood as an electronic component configured to pass signals having frequencies lower than the cutoff frequency and reduce or suppress signals having higher frequencies.

Demodulation may further include filtering the detector signal by using at least one band pass filter prior to multiplying the detector signal by the modulation frequencies. A band pass filter is an electronic device configured to allow frequencies within a predetermined range to pass and reject other frequencies outside this range. The band pass filter may be adjustable. Accordingly, it may be possible to adjust the passband to the frequencies used in the measurement.

The method includes error detection based on a comparison of at least two demodulated detector signals. Error detection may be used as recognizing disturbances, in particular disturbances due to one or more of the ambient light, disturbances of one or more of the light sources, and disturbance of one or more electronic components. Other disturbances are feasible. As used herein, error detection based on a comparison of at least two demodulated detector signals generally implements one result of the comparison as an error detection algorithm as a variable and/or as a parameter, so that error detection is any suitable. Refers to the fact that comparison by means is taken into account. Thus, as an example, as schematically illustrated in more detail below, error detection may imply comparing one or more variables to at least one threshold, wherein one or more variables are at least one of the comparisons. The results may be implied.

In addition, error detection may provide the possibility to determine a reliable measurement value of the photometric measurement in the presence of ambient light and/or in the event of rejection of the measurement. Error detection may be online error detection performed permanently or repeatedly. Error detection may be repeated once or several times during the photometric measurement.

Error detection is based on a comparison of at least two demodulated detector signals. In general, as used herein, the comparison of at least two demodulated detector signals depends on the magnitude of each of the demodulated detector signals, and/or the difference between the demodulated detector signals in two norms. Refers to an algorithm configured to generate a comparison result that is dependent on forming s. Thus, as an example, the comparison may imply forming a difference between at least two demodulated detector signals, and/or imply forming a quotient of at least two demodulated detector signals. May be. For demodulated detector signals, each containing a series of single values, the comparison may imply comparing the current or immediate value of the series. As an example, the comparison comprises: comparing at least one of the demodulated detector signals with at least another one of the demodulated detector signals; Comparing at least one of the demodulated detector signals with an average value of at least one of the demodulated detector signals; It may include at least one algorithm selected from the group consisting of a comparison between at least one of the demodulated detector signals and at least one threshold value. Accordingly, in general, the demodulated detection signals may be compared directly to each other, for example, may be compared with at least one representative value representing a normal condition and/or representing an entity of the demodulated detector signals.

In general, as outlined above, error detection may imply at least one threshold comparison. Thus, as an example, the difference between one or more of the demodulated detector signals and/or the difference between at least two demodulated detector signals and/or the quotient of the two or more detector signals is directly or indirectly with one or more threshold points. It can also be compared.

Error detection may include detecting erroneous demodulated detector signals. A demodulated detector signal may be recognized as erroneous if at least two generated demodulated detector signals exhibit inconsistencies greater than a predetermined tolerance. In an embodiment, more than two, for example three modulation frequencies may be used. Thus, one of the three demodulated detector signals is different from the other two modulated detector signals by a tolerance greater than the predetermined tolerance, whereas the two other demodulated detector signals show similar values. It may be perceived as being present. If all the demodulated detector signals differ by a tolerance greater than the predetermined tolerance, the entire set of demodulated signals may be detected as erroneous.

The comparison of the at least two demodulated detector signals comprises comparing at least a first demodulated detector signal of the demodulated detector signals with at least a second demodulated detector signal of the demodulated detector signals, and a first demodulated detector signal. Is different from the second demodulated detector signal by a tolerance greater than the predetermined tolerance, preferably by a tolerance of 0 to 2%, more preferably by a tolerance of 0 to 1%, the first demodulation It may include determining that the detected detector signal is erroneous.

Further, error detection may include rejecting demodulated detector signals that are recognized as erroneous demodulated detector signals, and using only error-free demodulated detector signals to determine the concentration of at least one analyte in body fluid. It can also be implied. If one of the demodulated detector signals is detected as erroneous, this demodulated detector signal is rejected to determine the concentration of at least one analyte in the body fluid. If the entire set of demodulated detector signals is detected as erroneous, the measurement is repeated with a new set of frequencies. In the latter case, a change in the set of frequencies may result in some settling time of the measuring devices, eg band pass filters. The demodulated detector signals may each be a sequence of measurement values, wherein rejecting erroneous demodulated detector signals comprises: rejecting a current measurement value determined to be erroneous; It may include a rejection algorithm selected from the group consisting of rejecting the entire sequence of measurement values when it is determined that at least one of the measurement values is erroneous. The method may stop if all of the demodulated detector signals are determined to be erroneous. Further, each of the demodulated detector signals may comprise a sequence of single measurement values, where error detection may be based on a comparison of single measurement values. A single measurement can be understood as raw, un-evaluated and/or non-analyzed data. For example, single measurement values are issued by the detector every 20 ms, preferably every 10 ms.

In addition or alternatively to the above-mentioned error detection, it may include detecting erroneous demodulated detector signals. Fault detection may include determining a degree of faultiness for demodulated detector signals that are determined to be faulty. Accordingly, it is possible that at least one erroneous demodulated detector signal may be used to determine the concentration of the analyte, where the degree of error is taken into account.

The method may be performed iteratively, where, in one of the iterations of the method, if an erroneous demodulated detector signal is obtained for a specific modulation frequency, the modulation frequency may not be used in a later iteration of the method. . In general, if an erroneous demodulated detector signal is obtained for a particular modulation frequency, it is possible to change it to another frequency that has not been used so far. However, then, settling times will occur.

In the above-mentioned embodiment in which two or more light sources each modulated by at least two modulation frequencies may be used, the error detection is demodulated detector signals for the modulation frequencies that cause the first light source to be modulated, and It may be performed on both of the demodulated detector signals for the modulation frequencies that cause the second light source to be modulated. Thus, for example, in one set of demodulation frequencies for modulation frequencies that cause a light source selected from a group of first and second light sources to be modulated, if one or more demodulated detector signals are detected as erroneous, and Even when an erroneous demodulated detector signal has not been detected, by using only the light of the erroneous light source, at a different set of demodulation frequencies for the modulation frequencies that cause another light source selected from the group of first and second light sources to be modulated, Reliable measurements of the concentration of the analyte may be possible.

Error detection may be performed at least once prior to applying a sample of bodily fluid to the test carrier. As outlined above, the method is specifically, for example, as suggested in method step a), prior to application of a sample of bodily fluid to a test carrier, before performing method steps a) to d). It may be performed in whole or in part, and/or may comprise additional steps which may be performed at least once independently from method step a).

Accordingly, the method may further include determining at least one dry empty value by evaluating at least one detector signal generated by the detector prior to applying the sample of bodily fluid to the test carrier. Conducting a measurement of conveyance of the test carrier prior to application of a sample of body fluid, the so-called dry empty value, is well known to those skilled in the art. Error detection may be performed at least once while determining the dry empty value. To determine the usability of the test carrier, the dry empty value may be compared to reference values. If the availability of the test carrier may be limited due to defects, e.g., aging defects caused by environmental influences such as humidity, light, or temperature, apply the test carrier before applying a sample of body fluid to the It may be possible to reject and/or adjust one or more of the measured values, such as at least one detector signal and a determined concentration of analyte.

Additionally or alternatively, the method may further comprise at least one location verification step, wherein the location verification step may comprise the following method steps:

i) inserting the test carrier into the analysis device;

ii) illuminating the test carrier by at least one light source;

iii) receiving the light carried by the test carrier by using at least one detector;

iv) determining at least one location of the test carrier in the analysis device by evaluating at least one detector signal generated by the detector, the location comprising at least one of a location and/or orientation of the test carrier. Determining at least one location of the carrier.

The method steps may be performed in a predetermined order, that is, in the order i)-ii)-iii)-iv). However, other sequences of method steps are feasible, such as ii)-i)-iii)-iv). Thus, as an example, the test carrier may be or include a strip-shaped test carrier or test tape that may be inserted into the container of the analysis device prior to illuminating the test carrier by at least one light source. . Additionally or alternatively, a test carrier, such as a test tape and/or test strip, may comprise one or more of at least one marking, at least one coating, and/or at least one other item of information. May be. The at least one item of information may include at least one item of visually detectable information that may be detected by the at least one analysis device. The at least one item of information may comprise at least one item of information regarding the proper use of the test carrier, such as at least one calibration information, and/or a positioning mark or fiducial mark. It may also include at least one item of other information such as. The analysis device may be equipped for reading at least one item of information, for example during insertion of the test carrier into the analysis device and/or within the analysis device. The analysis device may further be provided for evaluating at least one item of information and/or for controlling at least one process according to at least one item of information. Accordingly, the analysis device may be equipped to control the positioning of the test carrier and/or to detect whether the test carrier is positioned correctly. As an example, the analysis device illuminates the test tape, detects at least one marking on the test tape, and/or to control the positioning of the test tape and/or to detect whether the test tape is positioned correctly, and/or Alternatively, it may be provided to detect at least one test field on the test tape. Control of the positioning of the test tape may be performed by controlling an appropriate supply mechanism of the analysis device, for example, by controlling a motor for positioning the test tape. Thus, in particular, in the latter case, the illumination of the test carrier may occur before or during insertion of the test carrier into the analysis device, for the purpose of monitoring the insertion process itself, for example a positioning process.

Also, for example, by performing at least partially concurrently with method steps i) and ii) and/or by performing at least partially concurrently with method steps ii), iii), and iv), one or more of the method steps may be It may be performed in parallel and/or in a timely overlapping manner. Further, one or more of the method steps may be performed repeatedly. Accordingly, as an example, method steps ii) and/or iii) may be performed repeatedly. In addition, there may be additional method steps not listed.

The test carrier may be inserted into the container of the assay device. The test carrier and/or analysis device and/or light source and/or detector may specifically be identical to the respective devices used in method steps a) to d). Additionally or alternatively, however, at least one additional light source and/or at least one additional detector is dedicated to the position verification step. For the description of possible embodiments and definitions of these devices, reference may be made to the above-mentioned devices used in methods a) to d) and to the above-mentioned analysis device according to the invention. In general, other configurations of these devices may be possible.

The location verification step may be performed prior to performing method steps a) to d). The location verification step comprises determining, within the analysis device, a location and/or orientation of the test carrier, including the possibility of determining a location or location of a portion thereof, such as a location or location of at least one test field of the test carrier. May be. As outlined above, method steps i) to iv) may be performed at least once prior to applying a sample of bodily fluid to the test carrier, such as before performing a combination of method steps a) to d). . In this embodiment, method steps i) to iv) may be performed at least once prior to applying a sample of bodily fluid to the test carrier to determine at least one location of the test carrier within the assay device. The test carrier and/or the test field of the carrier may comprise a marking, eg, a color marking, and/or another optional marking, eg, with a known conveyance. As used herein, “location” refers to the location and/or orientation of a test carrier, or a portion of a test carrier, such as at least one test field of a test carrier, and/or within an analysis device, such as within a container of an analysis device. It may be the marking of the test carrier. Test carriers, such as test strips, test tapes, test disks, and integrated test carriers, and/or the conveyance of light in the test field of the carrier may be dependent on its location within the analysis device. Proper alignment within the analysis device may be required for reliable measurement values.

After performing method steps i) to iv), the determined measured values, eg, one or more of the at least one detector signal and the determined concentration of the analyte, may be compared to reference values. If the test carrier is properly aligned, the determined measurement values may correspond to reference values, within specified limits (such as within one or more threshold points).

The determination of the location may be performed once before applying the sample of bodily fluid to the test carrier and/or once during the photometric measurement. Because of this, if the test carrier is not properly aligned within the assay device, stopping the measurement at any desired time, e.g. before applying the sample to the test carrier, and/or measuring values, e.g. at least one It may be possible to adjust one or more of the determined concentration of the analyte and the detector signal of. If it is determined that the test carrier is not properly aligned within the analysis device, the alignment may be performed by the user and/or automatically. Further, if at least one or more of the modulation frequencies may be acceptable, the acceptable modulation frequency may not be considered for evaluation of the analyte concentration, and/or the set of frequencies may be varied. Further, error detection may be performed at least once during the determination of the position of the test carrier.

In some embodiments, the ambient light error detection step may be performed without using a test carrier. Herein, the method may further include at least one ambient light error detection step, wherein the ambient light error detection step may include the following method steps:

I. receiving ambient light by using at least one detector;

II. Evaluating at least one detector signal generated by the detector;

III. Performing ambient light error detection by comparing at least one detector signal generated by the detector with modulation frequencies.

The method steps are in a predetermined order, i.e., sequence I.-II. -III. It can also be done. However, II. -I.-III. As such, other orders of method steps are feasible. Also, for example, method steps I. and II. By performing at least partially concurrently, one or more of the method steps may be performed in parallel and/or in a timely overlapping manner. Further, one or more of the method steps may be performed repeatedly. In addition, there may be additional method steps not listed.

In other embodiments, ambient light detection may be performed after inserting the test carrier into the analysis device. Herein, the method may further include at least one ambient light error detection step, wherein the ambient light error detection step may include the following method steps:

I. inserting the test carrier into the analysis device;

II. Illuminating the test carrier with at least one light source;

III. Receiving ambient light by using at least one detector;

IV. Evaluating at least one detector signal generated by the detector;

V. Performing ambient light error detection by comparing at least one detector signal generated by the detector with modulation frequencies.

The method steps are in a predetermined order, i.e., sequence I.-II. -III. -IV. -Can also be performed with V. However, II. -I.-III. -IV. -As in V., different orders of method steps are feasible. Also, for example, method steps I. and II. At least partially simultaneously, and/or method steps II., III., and IV. By performing at least partially concurrently, one or more of the method steps may be performed in parallel and/or in a timely overlapping manner. Further, one or more of the method steps may be performed repeatedly. Thus, as an example, method steps II. And/or III. May be performed repeatedly. In addition, there may be additional method steps not listed.

In some embodiments, the first ambient light error detection step may be performed before inserting the test carrier into the analysis device, and the second ambient light error detection step may be performed after inserting the test carrier into the analysis device.

In all of these embodiments, the ambient light error detection step may be based on a comparison of the at least one detector signal with the modulation frequencies. As used herein, when referring to modulation frequencies in the context of ambient light error detection and comparison of at least one detector signal with modulation frequencies, the modulation frequencies are specifically, the detector signal at each of the modulation frequencies. They may be frequency components of or may include them. Accordingly, a full or partial frequency analysis of at least one detector signal may be performed, and thus frequency components of the detector signal may be derived, and specifically, frequency components of the detector signal may be derived at modulation frequencies. Consequently, as used herein, the expression "comparing at least one detector signal generated by the detector to the modulation frequencies" is generally referred to above, in order to determine whether at least one condition is met or not. It may also refer to the fact that the resulting frequency components may be evaluated. Accordingly, as outlined in more detail below, frequency components may be compared to one or more thresholds and/or one or more tolerance ranges and/or one or more conditions.

The ambient light error detection step may be performed prior to performing the method steps a) to d), for example before applying a sample of bodily fluid to the test carrier. Accordingly, in general, method steps I. to III. May be performed without inserting the test carrier into the assay device, for example by emptying the container of the assay device. Specifically, ambient light error detection may be performed without a test carrier, eg, without a test strip and/or without a test tape. Alternatively, the test carrier may be inserted into the analysis device, eg, into at least one container of the analysis device, and the step of detecting an ambient light error may comprise at least one step of inserting the test carrier into the analysis device. Accordingly, ambient light error detection may optionally occur in a realistic environment in which the test carrier is inserted into the analysis device.

The ambient light error detection may be performed without using the light source of the analysis device, for example by detecting only ambient light. Alternatively, ambient light error detection may be performed without additionally using at least one light source. Accordingly, when the test carrier is not inserted into the analysis device, the at least one light source may illuminate at least one empty vessel of the analysis device, and/or the test carrier, and/or the test field of the test carrier. It is also possible to illuminate at least one place or area within the analysis device that is normally occupied by a portion of the test carrier. Thus, in general, ambient light error detection may further imply illumination such as illumination of the analysis device and/or part thereof by using at least one light source. Consequently, the at least one detector signal generated by the detector may comprise at least one portion due to ambient light and at least one portion due to light generated by at least one light source of the analysis device.

If at least one test carrier is inserted into the analysis device for the purpose of ambient light error detection and/or during ambient light error detection, the process itself may further imply applying a sample of bodily fluid to the test carrier. In the latter case, ambient light error detection is specifically performed before applying a sample of bodily fluid to the test carrier, e.g., for the purpose of ambient light error detection, before detecting at least one detector signal and/or the light source is turned on. It may be performed before being turned on and/or after the light source is turned on. Other options are feasible.

The performance of ambient light error detection by comparing the at least one detector signal generated by the detector with the modulation frequencies, includes the frequency components of the at least one detector signal at the modulation frequencies, one or more threshold points and/or Comparisons such as mathematical comparisons with conditions and/or tolerance ranges may be further implied. For this purpose, the frequency components of the at least one detector signal are each individually or in a combined manner, as raw values, or after performing one or more preprocessing steps such as filtering or normalization, one or more threshold points. And/or conditions and/or tolerance ranges. As an example, two or more of the frequency components of the at least one detector signal are as raw signals, or after performing one or more preprocessing steps, e.g., a quotient and/or difference between two or more of the frequency components. It may be combined by using, and the result of this mathematical operation may be compared to one or more thresholds and/or conditions and/or tolerance ranges. Ambient light error detection may be dependent on the result of this comparison. Thus, as an example, if one or more thresholds are exceeded, and/or if the result is found to be outside one or more tolerance ranges, and/or if one or more error conditions are found to be satisfied, ambient light Errors due to may be detected, and optionally, one or more suitable actions may preferably be taken automatically, eg, providing an alert and/or preventing further measurements. Additionally or alternatively, if at least one detector signal, one or more of a plurality of detector signals, or at least one signal component of the at least one detector signal is found to be erroneous, for example due to disturbances by ambient light. , Each erroneous measurement signal or measurement signal component or each modulation frequency may be excluded from the method for determining the concentration of at least one analyte in a bodily fluid. Thus, as an example, ambient light error detection may determine whether one or more of the at least two modulation frequencies are such that the demodulated detector signals for each of the at least one modulation frequencies are erroneous, and the analyte concentration From the determination, it may be possible to exclude each of the at least one modulation frequency, which may be referred to as “faulty modulation frequency”. Thus, as an example, the erroneous modulation frequency may be replaced by another modulation frequency for the determination of the analyte concentration. Additionally or alternatively, at least one demodulated detector signal for an erroneous modulation frequency, which may also be referred to as “faulty demodulated detector signal”, may be excluded from further evaluation and/or other demodulated detector signal. It may be used with a lower weighting factor compared to the detector signals. The demodulated detector signals may be used to determine a weighted average value, specifically an average value of an analyte concentration such as a sliding average or a weighted sliding average. Averaging may occur before, during, or after determining the analyte concentration. Accordingly, the determination of the analyte concentration can be performed independently, e.g., by using the common correlation between the demodulated detector signals as input variables and the analyte concentration as output variables, and/or using the demodulated detector signals as input variables. To determine the analyte concentration independently, and later, for example, by determining the mean or average value or the weighted average value, by combining the independent results, one of the demodulated detector signals, more than one It may be performed on the basis of things, or all. Here, if one or more demodulated detector signals are determined as erroneous demodulated detector signals during ambient light error detection, the one or more erroneous demodulated detector signals may be excluded from the determination of the analyte concentration, and/or It may be used at a lower weight by using lower weighting factors in the weighted average compared to the missing demodulated detector signals.

The test carrier may be inserted into the container of the assay device. The test carrier, and/or the analysis device, and/or the light source, and/or the detector may be the same as the devices used in method steps a) to d). Additionally or alternatively, however, at least one additional light source and/or at least one additional detector is dedicated to the ambient light error detection step. For the description of possible embodiments and definitions of these devices, reference may be made to the above-mentioned devices used in methods a) to d) and to the above-mentioned analysis device according to the invention. In general, other configurations of these devices may be possible.

The expression “ambient light” may be understood as light emitted by arbitrary light sources present during carrying out the proposed method, eg sunlight, light of artificial light sources. The ambient light error detection step may be performed to determine a contribution of one or more possible modulation frequencies in the ambient light, eg, prior to performing method steps a) to d).

The detector may receive ambient light and may generate at least one detector signal. The at least one detector signal generated by the detector may be evaluated for the contribution of one or more possible modulation frequencies in the ambient light. The evaluation may include comparing the at least one detector signal to at least one modulation frequency and/or a set of modulation frequencies, which may be used to modulate the light source. If the ambient light represents contributions of at least one modulation frequencies that may be used to modulate the light source, then at least one modulation frequency may not be considered for the evaluation of analyte concentration, and/or the set of frequencies It can be changed.

As outlined above, method step d) implies determining the concentration of the analyte by evaluating at least one detector signal generated by the detector. As used herein, evaluation of at least one detector signal generally refers to an arbitrary algorithm for deriving the concentration of an analyte from at least one detector signal. The algorithm may be an analysis algorithm such as an evaluation function or may include an analysis algorithm. Additionally or alternatively, any other type of algorithm may be used, such as a lookup table or any other algorithm provided to assign a specific value of the detector signal to the concentration of the analyte. These algorithms are generally well known to those skilled in the art. As an example, the end value of a measurement curve comprising a sequence of detector signals may be used as a characteristic value, and the analyte concentration may be derived therefrom. Accordingly, as an example, an algorithm as disclosed in EP 0 821 234 and US 2002/0146835 A1 may be used, in which a measurement curve is compared directly or indirectly with one or more threshold points. Thus, as an example, EP 0 821 234 B1 discloses a method in which the slope of a measurement curve is determined by deriving difference values of colors and comparing these difference values with a predetermined threshold. Thereby, the end point of the detection reaction may be determined. Similarly, in US 2002/0146835 A1, the final value is the calculation of the intermediate analyte level of the testing element at predetermined intervals, and the ratio value corresponding to the (n)th measurement to the (n-5)th measurement It is determined by calculating. When two successive ratio values are less than or equal to the predetermined value, it is considered to have reached the final value, and the final analyte level can be determined.

In addition, some evaluation algorithms using one or more fitting algorithms are known in the art, in which a measurement curve containing detector signals is analyzed by using one or more fit functions. Accordingly, in WO 2011/061257 A1, a method and device for analyzing bodily fluids in which a photometric curve is measured are disclosed. The transmission behavior of the optical transmission system is controlled by detecting measured values at two different measurement wavelengths. Further, fit functions are generated for two measurement curves, and by extrapolating the fit curves, the offset of the measurement values is determined. In US 2008/0087819 A1 also a method for analyzing a fluid sample is disclosed, in which two different wavelengths are used to derive two measurement curves. Measurement curves are fitted using an exponential rise with an exponential fall, by performing an appropriate fit algorithm with two different types of temporal constants.

In WO 01/25760 A1 a timing-independent method is disclosed for determining an appropriate time for the measurement of the reaction between a sample fluid and a reagent on an analyte strip. Here, the measurement curve of the properties of the matrix to which the sample fluid is applied is periodically measured both before and after the application of the sample fluid. Later, a transformation of this measurement curve into various functions is made that is independent in time or linearly as maximally in time. Next, the second derivative of the transformed function is analyzed to determine when the second derivative falls within a predetermined critical point. At this point, the transformed function will yield the analyte concentration in the sample fluid. In EP 1 413 883 A1 a method for reducing the analysis time of endpoint-type reaction profiles is disclosed. For this purpose, at three different time points, a detection reaction is undertaken that obtains at least three measurements of the level or value of an observable associated with the detection response. Later, the endpoint value for the observable is estimated from the measurements by using an appropriate fit function. In WO 2006/138226 A2 an arrangement and algorithm for calculating the concentration of an analyte contained in a sample is disclosed. Here, the rate of color change of the test chemical is detected, and the hematocrit is derived from the rate of color change. An appropriate correcting factor, indicating the red blood cell volume, is used to correct the glucose concentration.

These algorithms and/or any other evaluation algorithm known to those skilled in the art may be used to perform method step d), where in some embodiments, only error-free detector signals are used to determine the analyte concentration. It is used in method step d).

Step d) of the method may be further performed by using a data processing device and/or a computer. For example, error detection may be performed by using a data processing device and/or a computer, in particular a comparison of demodulated detector signals.

In addition, it may be possible to store information of error detections for certain frequencies and/or reoccurring error detections for certain frequencies. Accordingly, the method may imply storing information about previous error detection in at least one data memory for use in future measurements. As an example, information about one or more modulation frequencies known to be erroneous and/or known to be erroneous may be stored in at least one data memory. Accordingly, it may be possible to start the measurement with unacceptable or error-free frequencies. The method may be performed, either automatically or by manual adjustment by a user, such that one or more modulation frequencies that are known to be error-free from, for example, previous measurements are selected. Accordingly, the analysis device performing the method may be equipped to provide a user with two or more modulation frequencies, and/or two known to be error-free, at least from previous measurements, e.g., without the need for user input. It may be provided to automatically select the above reliable modulation frequencies.

In certain embodiments, the method further comprises one or more or even all of the following method steps, which may be performed prior to performing method step a) in an embodiment, i.e., prior to applying a sample of bodily fluid to the test carrier. You can also include:

i. Inserting the test carrier into the analysis device;

ii. Initiating error detection;

iii. Acquiring a dry empty value.

As outlined above for method steps a) to d), these method steps i. To iii. May be performed in any order and/or in any feasible order, as will be apparent to those skilled in the art. Further, one or more or even all of these additional method steps may be combined with one or more of the method steps a) to d).

For further details of the analysis device, reference may be made to the disclosure of the second aspect of the invention as given below.

The method according to the invention, as will be apparent to the person skilled in the art, basically allows to carry out error detection at any reasonable time of the photometric measurement. It may also be possible to avoid erroneous or inaccurate measurement values caused by disturbance of the ambient light by changing from the allowable frequencies used to the non-acceptable frequencies. This is achieved, on the one hand, by comparing the demodulated detector signals at the very early stage of the measurement, for example, during the determination of the dry empty value, instead of comparing the evaluated value of the concentration of the analyte. Also, this is achieved by using more than one set of modulation frequencies. Accordingly, it is possible to change the set frequencies in case of error detection. In general, the amount of frequency changes is not limited. However, the settling time of the measuring devices used may have to be considered.

In addition, the described error detection at the very early stage of the measurement offers the possibility to ensure the robustness of the determined concentration value of the analyte by detecting disturbances before applying a sample of bodily fluid to the test carrier. Pre-selection of a set of frequencies may be possible by performing one or more frequency changes and/or one or more error detections prior to applying a sample of bodily fluid to the test carrier. Accordingly, a set of frequencies having the lowest allowability can be preselected.

For example, the method may be performed with two modulation frequencies 1,488 kHz and 1,587 kHz. If the demodulated detector signal generated during the determination of the dry empty value for this set of frequencies exhibits inconsistencies that exceed a certain threshold value, this pair may be detected as erroneous or may be rejected. In this case, the set of frequencies may be changed to another set of frequencies, for example 1,302 kHz and 1,389 kHz. Also, if this set of frequencies exhibits inconsistencies exceeding a certain threshold, this pair may be detected as erroneous and may also be rejected. Also, the second set of frequencies may be varied to another set of frequencies, for example 1,645 kHz and 1,754 kHz. If the third set of frequencies is not detected as erroneous, the sample will be applied to the carrier and measurement of the concentration of the analyte will begin.

Additionally or alternatively to the comparison of the demodulated detector signals with one threshold value, two or more threshold values may be established. The at least one threshold value may be or include at least one predetermined threshold value, and/or may be or include at least one adjustable threshold value that may be manually and/or automatically adjustable. For example, one narrow threshold value, e.g., a deviation of the demodulated detector signals of 0.5%, and one wider threshold value, e.g., a deviation of the demodulated detector signals of 1 to 2%. If the deviation of the demodulated detector signals lies within a narrow threshold range, an alert may be generated to display to the user that the measurement is suspicious. Instead, if the deviation of the demodulated detector signals lies within a wider threshold range, a change in the allowable frequency or interruption of the measurement may be performed.

In yet another embodiment, more than two frequencies may be used for modulation of the light source. For example, three, four, or more than four frequencies, such as f _i , f _ii , f _iii , may be used for modulation of the light source. In this embodiment, three demodulated detector signals for three modulation frequencies may be generated or compared. Because of this, if only one of the frequencies is acceptable, it may be possible to use only error-free demodulated detector signals for the evaluation of analyte concentration. The resulting detector signal may be determined as an average value of the error-free demodulated detector signals. For example, if the frequency f _i is acceptable and f _ii and f _iii are not, it may be possible to consider only _{frequencies f ii} and f _iii for the evaluation of analyte concentration. As an example, the method may only stop if all of the three demodulated detector signals exhibit different values. Accordingly, it may be possible to determine the concentration of the analyte even in case of error detection for one of the frequencies without changing the entire set of frequencies.

For example, in one embodiment, two light emitting diodes may be used as light sources. The signal of one of the light sources may be modulated at three frequencies, eg, f _1a = 977 Hz, f _1b = 1465 Hz, and f _1c = 1953 Hz. The signal of a different light source may be modulated with three different frequencies, eg, f _2a = 1172 Hz, f _2b = 1563 Hz, and f _2c = 2344 Hz. During error detection, in a first step, the demodulated detector signals of _{f 1a} and f _{1b may be compared.} In a second step, these demodulated detector signals may be compared with a demodulated _{detector signal of f 1c.} The average detector output signal may only be evaluated from the same values, and the same indicates that it is the same within some threshold. For evaluation of the average detector output signal, at least two values may be required. If all of the demodulated detector signals differ from those greater than the predefined threshold value, an error value may be generated, and a change to other than acceptable frequencies may be performed. The same method may be applied to the frequencies of the second light source. The two determined average values may be further evaluated to determine the concentration of the analyte. In this later stage of the measurement, it may be additionally possible to compare the two determined concentrations of the analyte. If the two measurement results are not the same, a warning and/or error value may be issued.

In a further aspect of the invention, an assay device is disclosed for determining the concentration of at least one analyte in a bodily fluid, comprising at least one container for receiving at least one test carrier. As used herein, generally, an assay device refers to a device that is equipped to perform at least one assay to determine the concentration of one or more analytes in a bodily fluid. The analysis device may be a hand-held device, or may be a stationary or portable device.

At least one sample of bodily fluid is applicable to the test carrier. To achieve this aspect, the assay device may be adjusted such that a sample of bodily fluid may be applied to the test carrier prior to insertion of the test carrier into the container and/or with the test carrier being inserted into the container. In the first case, the container may be designed such that the test carrier to which the sample has been applied may be inserted into the container. In the latter case, the container may be designed such that at least one portion of the test carrier having at least one application location is accessible to the user in order to allow application of the sample.

The analysis device may be equipped to perform the method according to the method described in the first aspect of the invention. For the description of possible embodiments and definitions, reference may be made to the above-mentioned method according to the invention.

As used herein, the container may be an optionally formed device configured to allow insertion of a test carrier. The container may be further provided to enable application of a sample of bodily fluid to the test carrier. The container may generally comprise at least one means for holding the test carrier in at least one predetermined position. Accordingly, as an example, the container may include one or more of a slot, a guide structure, a holder, and a chamber. Other types of containers are feasible. The container may be equipped to hold the test carrier in position during photometric measurements. The container may include at least one opening provided to insert the test carrier into the container, such as one or more of a slotted opening, a rectangular opening, and a circular opening.

The analysis device further comprises at least one light source provided for illuminating the test carrier and at least one detector provided for receiving light carried by the test carrier. For potential embodiments of a light source, reference may be made to the definitions and embodiments given above or given in more detail below.

The analysis device further comprises at least one evaluation unit provided for determining the concentration of the analyte by evaluating at least one detector signal generated by the detector. As used herein, an evaluation unit generally refers to a device or system of multiple devices configured to evaluate at least one detector signal generated by the detector. For example, the evaluation unit may comprise a data processing device and/or a computer. Accordingly, as an example, the microprocessor may be integrated in the evaluation unit. Additionally or alternatively, external data-processing devices, such as one or more personal computers, one or more computer networks, or one or more other types of data processing devices may be included into the analysis device.

The analysis device further comprises at least one modulation device provided for modulating the light source by using at least two modulation frequencies. As used herein, a modulation device generally refers to at least one device configured to perform modulation as defined above. Accordingly, the modulating device may in general be arranged to be periodically modulated at at least one light source and/or at least one parameter of light emitted by the at least one light source.

The signal source may be provided to generate one or more control signals having at least two modulation frequencies. In particular, the modulation device is provided to modulate the light source by using at least three modulation frequencies.

The analysis device comprises at least one demodulation provided for demodulating the detector signal to at least two modulation frequencies, in order to generate at least two demodulated detector signals, each demodulated detector signal corresponding to one of the modulation frequencies It further includes a device. As used herein, a demodulation device generally refers to a device configured to perform a demodulation process as defined above. Accordingly, the demodulation device may be equipped to demodulate a signal that has been modulated by at least two modulation frequencies. The demodulation device may be arranged such that demodulation includes independently multiplying the detector signal by one or more modulation frequencies and filtering the results by using one or more low-pass filters. In addition, the demodulation device may be arranged such that the demodulation includes filtering the detector signal by using at least one band pass filter before multiplying the detector signal by the modulation frequencies. In some embodiments, the band pass filter is manually and/or automatically adjustable.

The demodulation device may include at least one lock-in amplifier. For example, the lock-in amplifier may be or may include a single phase lock-in amplifier. A single phase lock-in amplifier may include a single lock-in structure using one reference signal. In an embodiment, the lock-in amplifier may be a digital dual phase lock-in amplifier, eg, to be phase independent. The digital dual phase lock-in amplifier may include a double lock-in-structure. A double lock-in structure may comprise two single lock-in-structures, each containing a reference signal. The reference signal may have the same modulation frequency that causes the light source to be modulated, and/or may be modulated with this same modulation frequency. One of the reference signals of the double lock-in structure may be shifted, and for example, the reference signal may be shifted by 90°. The output signal of the dual phase lock-in amplifier may be dependent on the square root of the sum of the squared individual signals. As used herein, the term “lock-in amplifier” may be used as a synonym for a dual phase lock-in amplifier.

The analysis device further comprises at least one error detection device provided for performing error detection based on a comparison of the at least two demodulated detector signals. The error detection device is a device or system of devices configured to perform the error detection described above. The error detection device may comprise a data processing device and/or a computer. The error detection device may wholly or partially be part of the evaluation device, and/or may be embodied in whole or in part as a separate device. Further, the error detection device may be provided to perform error detection as an online error detection, which may be performed permanently or repeatedly. As used herein, online error detection generally refers to error detection performed during the measurement procedure of photometric measurements, such as during determination of analyte concentration.

For details of potential embodiments of error detection, reference may be made to the disclosure of the method as given above and/or as given in more detail below. The error detection device comprises: a comparison of the at least two demodulated detector signals comprising: a comparison of at least one of the demodulated detector signals with at least another of the demodulated detector signals; Comparing at least one of the demodulated detector signals with an average value of at least one of the demodulated detector signals; It may be provided to include at least one algorithm selected from the group consisting of a comparison between at least one of the demodulated detector signals and at least one threshold value. For example, the error detection device, wherein the comparison of the at least two demodulated detector signals compares at least a first demodulated detector signal of the demodulated detector signals with at least a second demodulated detector signal of the demodulated detector signals. And the first demodulated detector signal by a tolerance greater than a predetermined tolerance, preferably by a tolerance of 0 to 2%, more preferably by a tolerance of 0 to 1%, the second demodulated detector signal In the case of a difference from, it may be provided to include determining that the first demodulated detector signal is erroneous.

In general, an error detection device may be provided such that error detection includes detecting erroneous demodulated detector signals. In certain embodiments, the error detection device further comprises, wherein error detection rejects erroneous demodulated detector signals, and uses only the error-free demodulated detector signals to determine the concentration of at least one analyte in the bodily fluid. It may be provided so as to. As used within the present invention, rejection refers to a process that prevents further use of a demodulated detector signal that is generally perceived as erroneous. Rejection may be an automatic rejection that automatically prevents the use of an erroneous demodulated detector signal. Additionally or alternatively, the rejection may be semi-automatic and/or manual rejection, for example by providing a warning to the user indicating that a particular modulation frequency or demodulated detector signal is erroneous.

In particular, the demodulation device may include, wherein the demodulated detector signals each comprise a sequence of measurement values, wherein rejecting erroneous demodulated detector signals comprises: rejecting a current measurement value that is determined to be erroneous; It may be provided to include a rejection algorithm selected from the group consisting of rejecting the entire sequence of measurement values when it is determined that at least one of the measurement values is erroneous. The analysis device may be equipped to stop determining the concentration of the analyte if it is determined that all of the demodulated detector signals are erroneous. In addition, the analysis device may be equipped to issue an output indicating the interruption if the determination of the concentration of the analyte is interrupted.

Further, additionally or alternatively, the error detection device may be provided to include determining an error degree for the demodulated detector signals for which the error detection is determined to be erroneous. The evaluation unit may be equipped such that at least one erroneous demodulated detector signal is used to determine the concentration of the analyte, where the degree of error is taken into account.

In some embodiments, the at least one light source is modulated by at least one first light source modulated by at least two modulation frequencies, and at least two modulation frequencies different from at least two modulation frequencies that cause the first light source to be modulated. It may also include at least one second light source that is modulated. For each light source, at least two signals, each having a modulation frequency, may be generated by the signal source. In the mixer unit, one control signal for controlling is generated by mixing, in particular adding, two signals for each light source. Each of the two light sources may be controlled by one of the generated control signals or may illuminate the test carrier. The conveyed light may be detected by a detector. In this embodiment, the demodulation device is generated for modulation frequencies where at least two demodulated detector signals cause the first light source to be modulated, wherein at least two demodulated detector signals are modulated to cause the second light source to be modulated. It may be provided to be generated for frequencies. To this end, the error detection device is configured with respect to both the demodulated detector signals for the modulation frequencies that cause the first light source to be modulated, and the demodulated detector signals for the modulation frequencies that cause the second light source to be modulated. It may be provided to be performed.

In yet another embodiment, the demodulation device may be provided such that each of the demodulated detector signals comprises a sequence of single measurement values, wherein the error detection device is provided such that error detection is based on a comparison of the single measurement values. May be. The advantage of comparing single measurement data is that this measurement data may be quickly available as the comparison occurs at the early stage of the measurement, and evaluation steps such as calculations and/or integrations are not determined.

The error detection device may be provided such that error detection is performed at least once before applying a sample of bodily fluid to the test carrier. The analysis device may be provided to determine at least one dry empty value by evaluating at least one detector signal generated by the detector prior to applying a sample of bodily fluid to the test carrier. The error detection device may be provided such that error detection is performed at least once while determining the dry empty value. Accordingly, error detection may be performed prior to determination of the concentration of the analyte in the body fluid. Because of this, it may be possible to stop the measurement before applying the sample to the test carrier, so that the inserted test carrier is still available and not rejected.

In a further aspect of the invention, an assay system is disclosed for determining at least one analyte in a bodily fluid comprising the assay device described above. Thus, in general, an assay system as used herein may be treated independently or in combination, and may cooperate to determine the concentration of at least one analyte in at least one body fluid. It refers to a combination of at least one analysis device and at least one test carrier as phosphorous entities. For the description of possible embodiments and definitions, reference may be made to the above-mentioned method according to the invention and to the above-mentioned analysis device.

The analysis system includes at least one test carrier. The test carrier may be selected from the group consisting of a test strip, a test tape, a test disk, and an integrated test carrier having at least one test chemical and at least one lancet element.

As used herein, the lancet element may be an optional element configured to puncture and/or cut the user's skin to create at least one sample of bodily fluid. The lancet element may include one or more of a circular tip, a sharp tip, a flat tip, a needle, and an edge. The lancet element may comprise additional elements, for example elements configured to sample and/or transport a sample of bodily fluid, in particular a capillary tube.

The test carrier may include at least one substrate and at least one test chemical applied to the substrate, wherein the test chemical performs at least one detection reaction in the presence of the analyte to be detected and due to detection It may be provided to change at least one optically detectable property. The optically detectable attribute may be an arbitrary optical attribute that changes due to the detection reaction, and the measurement of this optical attribute may therefore provide at least one item of information about the progress, limit, or situation of the detection reaction. have. In some embodiments, the at least one optically detectable information includes color; It is selected from the group consisting of reflective properties such as transport and phosphorescence of the test chemical. Other embodiments are feasible.

As detailed above, the light source may use at least two frequencies. The described devices and/or system allow reliable measurement results even in case of disturbances. The described devices and/or system are operable even when using and/or detecting erroneous frequencies.

The invention provides, in one or more of the embodiments enclosed herein, when a program is executed on a computer or a computer network, on a processor residing in an analysis device, a computer-executed method for performing the method according to the invention and/or parts thereof. It further discloses and proposes a computer program containing possible instructions. Specifically, the computer program is on a computer-readable data carrier, such as a computer-readable data carrier and/or a ROM (such as a Flash-ROM) of the test carrier, for example a ROM such as a flash-ROM. It can also be stored on top. Thus, specifically, one, more than one, or even all of the method steps a) to d) as indicated above, preferably by using an analysis device, a computer, or a processor residing within a computer network, preferably , May be performed by using a computer program. Specifically, one or more of determining the concentration of the analyte as disclosed in method step d), demodulation of at least one detector signal, and error detection is performed by using an analysis device, a computer, or a processor residing within a computer network. It could be.

The invention provides, in one or more of the embodiments enclosed herein, when a program is executed on a computer or a computer network, on a processor residing in the analysis device, in order to perform the method according to the invention and/or parts thereof, the program code It further discloses and proposes a computer program product having means. Specifically, the computer code means may be stored on a computer-readable data carrier.

In addition, the invention is invented in accordance with one or more of the embodiments disclosed herein after loading into an analysis device, a computer, or a data storage device residing within a computer network, such as into a working memory or main memory of a computer or computer network. And/or some of them may be implemented.

The invention is a machine-readable method for performing a method and/or portions thereof, according to one or more of the embodiments disclosed herein, when a program is executed on a computer or a computer network, on a processor residing in an analysis device. It proposes and discloses a computer program product having a program code means stored on a -readable) carrier. As used herein, a computer program product refers to a program as a tradeable product. The product may generally reside in an arbitrary format, such as a paper format, or on a computer-readable data carrier. Specifically, the computer program product may be distributed over a data network.

Finally, the invention is directed to a modulation comprising instructions executable by an analysis device, a computer system, or a processor residing within a computer network to perform the invention and/or portions thereof, in accordance with one or more of the embodiments disclosed herein. Proposed and initiated the data signal.

Preferably, referring to computer-implemented aspects of the invention, one or more of the method steps or even all of the method steps of the method according to one or more of the embodiments disclosed herein are within an analysis device, a computer, or a computer network. It can also be done by using a resident processor. Accordingly, in general, any of the method steps including providing and/or manipulating data may be performed by using an analysis device, a computer, or a processor residing within a computer network. In general, these method steps may typically include any of the method steps other than method steps that require manual action, such as providing samples and/or certain aspects that perform actual measurements. .

Specifically, the present invention further discloses:

-An analysis device, computer, or computer network comprising at least one processor, the processor being adapted to perform a method and/or portions thereof, according to one of the embodiments described in this description. , Or a computer network,

-A computer loadable data structure adapted to perform a method and/or portions thereof, according to one of the embodiments described in this description, while the data structure is running on a computer,

-A computer program, wherein the computer program is arranged to perform a method and/or portions thereof, according to one of the embodiments described in this description, while the program is running on a processor resident in the analysis device, or while running on a computer. , The computer program,

-Program means for performing the method and/or parts thereof, according to one of the embodiments described in this description, while the computer program is running on a processor residing in the analysis device, on a computer, or on a computer network. Computer programs, including

-A computer program comprising program means according to the preceding embodiment, wherein the program means is stored on a storage medium readable by a computer,

-As a storage medium, the data structure is stored on the storage medium, and the data structure is loaded into the main and/or operational storage of an analysis device, a computer, or a computer network, and then in one of the embodiments described in this description. Accordingly, the storage medium provided to perform the method and/or parts thereof, and

-A computer program product having program code means, when the program code means is executed on an analysis device, on a computer, or on a computer network, the program code means according to one of the embodiments described in this description, the method and/or The computer program product, which may be stored on or stored on a storage medium to perform portions thereof.

Summarizing the findings of the present invention, reference is made in particular to the following embodiments:

Embodiment 1: a method for determining the concentration of at least one analyte in a body fluid, the method comprising:

a) applying a sample of bodily fluid to a test carrier;

b) illuminating the test carrier by using at least one light source;

c) receiving the light carried by the test carrier by using at least one detector;

d) determining the concentration of the analyte by evaluating at least one detector signal generated by the detector;

At least one light source is modulated by using at least two modulation frequencies, the detector signal is demodulated with at least two modulation frequencies to produce at least two demodulated detector signals, and each demodulated detector signal is modulated with modulation frequencies. Corresponding to one of,

The method for determining the concentration of at least one analyte in a bodily fluid comprising error detection based on a comparison of at least two demodulated detector signals.

Embodiment 2: A method according to the preceding embodiment, wherein the error detection is permanently or repeatedly performed online error detection.

Embodiment 3: A method according to any of the preceding embodiments, wherein at least one light source is modulated by using at least three modulation frequencies.

Embodiment 4: a method according to any of the preceding embodiments, wherein the comparison of at least two demodulated detector signals is a comparison of at least one of the demodulated detector signals with at least another of the demodulated detector signals ; Comparing at least one of the demodulated detector signals with an average value of at least one of the demodulated detector signals; A method for determining a concentration of at least one analyte in a bodily fluid comprising at least one algorithm selected from the group consisting of comparing at least one of the demodulated detector signals with at least one threshold value.

Embodiment 5: A method according to any of the preceding embodiments, wherein the comparison of the at least two demodulated detector signals comprises at least a first of the demodulated detector signals, at least a first of the demodulated detector signals. 2 comparing with the demodulated detector signal, and the first demodulated detector signal by a tolerance greater than a predetermined tolerance, preferably by a tolerance of 0 to 2%, more preferably by a tolerance of 0 to 1%. And determining that the first demodulated detector signal is erroneous if it differs from the second demodulated detector signal.

Embodiment 6: A method according to any of the preceding embodiments, wherein error detection comprises detecting erroneous demodulated detector signals.

Embodiment 7: As a method according to the preceding embodiment, the error detection further comprises rejecting erroneous demodulated detector signals, and using only erroneous demodulated detector signals to determine the concentration of at least one analyte in bodily fluid. A method for determining the concentration of at least one analyte in a body fluid, comprising.

Embodiment 8: A method according to the preceding embodiment, wherein the demodulated detector signals are each a sequence of measurement values, and rejecting the erroneous demodulated detector signals comprises rejecting the current measurement value determined to be erroneous; A method for determining the concentration of at least one analyte in a bodily fluid comprising a rejection algorithm selected from the group consisting of rejecting the entire sequence of measurement values if at least one of the measurement values is determined to be erroneous.

Embodiment 9: A method according to any of the three preceding embodiments, wherein the method is stopped when all of the demodulated detector signals are determined to be erroneous. .

Embodiment 10: A method according to any of the four preceding embodiments, wherein error detection comprises determining a degree of error for the demodulated detector signals determined to be erroneous. Method for determining concentration.

Embodiment 11: A method according to the preceding embodiment, wherein the at least one erroneous demodulated detector signal is used to determine the concentration of the analyte, and the degree of error is taken into account. Way for you.

Embodiment 12: The method according to any of the six preceding embodiments, wherein the method is performed iteratively, and in one of the iterations of the method, when an erroneous demodulated detector signal is obtained for a specific modulation frequency, the A method for determining the concentration of at least one analyte in a body fluid, wherein the modulation frequency is not used in a later iteration of the method.

Embodiment 13: The method according to any of the preceding embodiments, wherein at least one light source is at least one first light source modulated by at least two modulation frequencies, and at least two modulations that cause the first light source to be modulated. A method for determining a concentration of at least one analyte in a bodily fluid comprising at least one second light source modulated by at least two modulation frequencies different from the frequencies.

Embodiment 14: A method according to the preceding embodiment, wherein at least two demodulated detector signals are generated for modulation frequencies that cause the first light source to be modulated, and at least two demodulated detector signals are generated for the second light source to be modulated. A method for determining the concentration of at least one analyte in a bodily fluid, generated for modulation frequencies.

Embodiment 15: A method according to the preceding embodiment, wherein error detection comprises demodulated detector signals for modulation frequencies causing the first light source to be modulated, and demodulated detector signals for modulation frequencies causing the second light source to be modulated. A method for determining the concentration of at least one analyte in a body fluid, performed on both.

Embodiment 16: A method according to any of the preceding embodiments, wherein each of the demodulated detector signals comprises a sequence of single measurement values, and the error detection is at least one in body fluid based on a comparison of the single measurement values. A method for determining the concentration of an analyte.

Embodiment 17: A method according to any of the preceding embodiments, wherein error detection is performed at least once prior to applying the sample of bodily fluid to the test carrier.

Embodiment 18: A method according to the preceding embodiment, the method comprising determining at least one dry empty value by evaluating at least one detector signal generated by the detector prior to applying a sample of bodily fluid to a test carrier. A method for determining the concentration of at least one analyte in a body fluid, further comprising.

Embodiment 19: A method according to the preceding embodiment, wherein the error detection is performed at least once during determining the dry empty value.

Embodiment 20: A method according to any one of the preceding embodiments, wherein the method further comprises at least one location verification step, wherein the location verification step comprises the following method steps:

i) inserting the test carrier into the analysis device;

ii) illuminating the test carrier by at least one light source;

iii) receiving the light carried by the test carrier by using at least one detector;

iv) determining at least one location of the test carrier in the analysis device by evaluating at least one detector signal generated by the detector, the location comprising at least one of a location and/or orientation of the test carrier. A method for determining the concentration of at least one analyte in a body fluid comprising the step of determining at least one location of the carrier.

Embodiment 21: The method according to any one of the preceding embodiments, wherein the method further comprises at least one ambient light error detection step, wherein the ambient light error detection step comprises the following method steps:

I. receiving light conveyed from the test carrier by using at least one detector;

II. Evaluating at least one detector signal generated by the detector;

III. A method for determining a concentration of at least one analyte in a bodily fluid comprising performing ambient light error detection by comparing at least one detector signal generated by the detector with modulation frequencies.

Embodiment 22: The method according to any one of the preceding embodiments, wherein the method further comprises at least one ambient light error detection step, wherein the ambient light error detection step comprises the following method steps:

I. inserting the test carrier into the analysis device;

II. Illuminating the test carrier with at least one light source;

III. Receiving ambient light by using at least one detector;

IV. Evaluating at least one detector signal generated by the detector;

V. A method for determining the concentration of at least one analyte in a body fluid comprising the step of performing ambient light error detection by comparing at least one detector signal generated by the detector with modulation frequencies.

Embodiment 23: A method according to any of the preceding embodiments, wherein demodulation comprises independently multiplying the detector signal by the modulation frequencies and filtering the results by using low-pass filters at least in body fluid. A method for determining the concentration of an analyte.

Embodiment 24: A method according to the preceding embodiment, wherein the demodulation comprises filtering the detector signal by using at least one band pass filter prior to multiplying the detector signal by the modulation frequencies. A method for determining the concentration of an analyte.

Embodiment 25: A method according to the preceding embodiment, wherein the band pass filter is adjustable.

Embodiment 26: The method according to any of the preceding embodiments, wherein the test carrier consists of a test strip, a test tape, a test disk, and an integrated test carrier having at least one test chemical and at least one lancet element. A method for determining the concentration of at least one analyte in a body fluid, selected from the group.

Embodiment 27: The method according to any of the preceding embodiments, wherein the test carrier comprises at least one substrate and at least one test chemical applied to the substrate, wherein the test chemical is in the presence of an analyte to be detected. A method for determining the concentration of at least one analyte in a bodily fluid, adapted to perform at least one detection reaction on and change at least one optically detectable property due to the detection reaction.

Embodiment 28: A method according to any of the preceding embodiments, wherein step d) is performed by using a data processing device and/or a computer.

Embodiment 29: A method according to any of the preceding embodiments, wherein error detection is performed by using a data processing device and/or computer.

Embodiment 30: A method according to one of the preceding embodiments, wherein the method comprises, for example, prior to performing method step a), the following method steps:

i. Inserting the test carrier into the analysis device;

ii. Initiating error detection;

iii. A method for determining the concentration of at least one analyte in a bodily fluid, further comprising at least one of obtaining a dry empty value.

Embodiment 31: an analysis device for determining the concentration of at least one analyte in a bodily fluid, wherein the analysis device comprises at least one container for receiving at least one test carrier, wherein the at least one sample of bodily fluid is a test carrier And the analysis device further comprises at least one light source provided to illuminate the test carrier, the analysis device further comprising at least one detector provided to receive light carried by the test carrier, The analysis device further comprises at least one evaluation unit provided for determining the concentration of the analyte by evaluating at least one detector signal generated by the detector, wherein the analysis device modulates the light source by using at least two modulation frequencies. And at least one modulation device provided for demodulation, the analysis device further comprising at least one demodulation device provided for demodulating the detector signal to at least two modulation frequencies to generate at least two demodulated detector signals. And each demodulated detector signal corresponds to one of the modulation frequencies, and the analysis device further comprises at least one error detection device provided to perform error detection based on a comparison of the at least two demodulated detector signals. An assay device for determining the concentration of at least one analyte in a bodily fluid.

Embodiment 32: An assay device according to the preceding embodiment, wherein the assay device is provided to perform a method according to any of the preceding method embodiments, wherein the assay device is for determining a concentration of at least one analyte in a bodily fluid.

Embodiment 33: An analysis device according to any of the preceding embodiments with reference to the device, wherein the evaluation unit comprises a data processing device and/or a computer. .

Embodiment 34: An analysis device according to any of the preceding embodiments with reference to the device, wherein the error detection device comprises a data processing device and/or a computer. device.

Embodiment 35: An analysis device according to any of the preceding embodiments with reference to a device, wherein the modulation device comprises at least one signal source.

Embodiment 36: An analysis device according to the preceding embodiment, wherein the signal source is provided to generate control signals having at least two modulation frequencies.

Embodiment 37: an analysis device according to any of the preceding embodiments with reference to the device, wherein the error detection device is permanently or repeatedly performed online error detection, at least one in bodily fluid provided to perform error detection. Analytical device for determining the concentration of an analyte of.

Embodiment 38: an analysis device according to any of the preceding embodiments referring to the device, wherein the modulation device is adapted to modulate the light source by using at least three modulation frequencies to determine the concentration of at least one analyte in body fluid. Analysis device for doing.

Embodiment 39: An analysis device according to any of the preceding embodiments referencing the device, wherein the error detection device comprises: a comparison of at least two demodulated detector signals with at least one of the demodulated detector signals, and a demodulated detector Comparison with at least another one of the signals; Comparing at least one of the demodulated detector signals with an average value of at least one of the demodulated detector signals; An analysis device for determining a concentration of at least one analyte in a bodily fluid, comprising at least one algorithm selected from the group consisting of comparing at least one of the demodulated detector signals with at least one threshold value.

Embodiment 40: An analysis device according to any of the preceding embodiments referencing the device, wherein the error detection device comprises: a comparison of the at least two demodulated detector signals comprising at least a first demodulated detector signal of the demodulated detector signals Comparing with at least a second demodulated detector signal of the demodulated detector signals, and by a tolerance in which the first demodulated detector signal is greater than a predetermined tolerance, preferably by a tolerance of 0 to 2%, more preferably Preferably, the concentration of at least one analyte in bodily fluid is provided to include determining that the first demodulated detector signal is erroneous if it differs from the second demodulated detector signal by a tolerance of 0 to 1%. Analysis device to determine the.

Embodiment 41: An analysis device according to any of the preceding embodiments with reference to a device, wherein the error detection device is provided such that error detection comprises detecting erroneous demodulated detector signals. Analytical device for determining the concentration of analyte.

Embodiment 42: the analysis device according to the preceding embodiment, wherein the error detection device rejects demodulated detector signals in which error detection is erroneous, and an error-free demodulated detector to determine the concentration of at least one analyte in body fluid. An assay device for determining the concentration of at least one analyte in a body fluid, further comprising using only signals.

Embodiment 43: As the analysis device according to the preceding embodiment, the demodulation device, wherein the demodulated detector signals are each a sequence of measurement values, and rejecting the erroneous demodulated detector signals determines a current measurement value that is determined to be erroneous. Rejection; An analytical device for determining the concentration of at least one analyte in a bodily fluid comprising a rejection algorithm selected from the group consisting of rejecting the entire sequence of measurement values if at least one of the measurement values is determined to be erroneous.

Embodiment 44: An analysis device according to any of the three preceding embodiments, wherein the analysis device is provided to stop determining the concentration of the analyte if all of the demodulated detector signals are determined to be erroneous. Analytical device for determining the concentration of at least one analyte of.

Embodiment 45: An analysis device according to any of the four preceding embodiments, wherein the error detection device is provided to include determining an error degree for the demodulated detector signals for which error detection is determined to be erroneous. Analytical device for determining the concentration of at least one analyte in a body fluid.

Embodiment 46: the analysis device according to the preceding embodiment, wherein the evaluation unit is provided such that at least one erroneous demodulated detector signal is used to determine the concentration of the analyte, and the error degree is taken into account at least one in body fluid. Analytical device for determining the concentration of an analyte of.

Embodiment 47: An analysis device according to any of the preceding embodiments with reference to a device, wherein at least one light source is at least one first light source modulated by at least two modulation frequencies, and the first light source is modulated. An analysis device for determining a concentration of at least one analyte in a bodily fluid, comprising at least one second light source modulated by at least two modulation frequencies different from the at least two modulation frequencies.

Embodiment 48: The analysis device according to the preceding embodiment, wherein the demodulation device is generated for modulation frequencies at which at least two demodulated detector signals cause the first light source to be modulated, and the at least two demodulated detector signals are second An analysis device for determining the concentration of at least one analyte in a bodily fluid, provided to be generated for modulation frequencies that cause the light source to be modulated.

Embodiment 49: The analysis device according to the preceding embodiment, wherein the error detection device comprises: demodulated detector signals for modulation frequencies at which error detection causes the first light source to be modulated, and modulation frequencies at which the second light source is modulated. An analysis device for determining the concentration of at least one analyte in a bodily fluid, adapted to be performed on both of the demodulated detector signals for.

Embodiment 50: An analysis device according to any of the preceding embodiments with reference to the device, wherein the demodulation device is provided such that each of the demodulated detector signals comprises a sequence of single measurement values, the error detection device comprising: An assay device for determining the concentration of at least one analyte in a body fluid, provided to be based on comparison of single measured values.

Embodiment 51: The analysis device according to any of the preceding embodiments with reference to the device, wherein the error detection device is provided such that error detection is performed at least once prior to applying a sample of the body fluid to the test carrier. Analytical device for determining the concentration of one analyte.

Embodiment 52: The analysis device according to the preceding embodiment, wherein the analysis device is configured to determine at least one dry empty value by evaluating at least one detector signal generated by the detector prior to applying a sample of bodily fluid to the test carrier. An analysis device for determining the concentration of at least one analyte in a body fluid.

Embodiment 53: the analysis device according to the preceding embodiment, wherein the error detection device is adapted to determine the concentration of at least one analyte in the body fluid, wherein the error detection is provided to be performed at least once while determining the dry empty value. Analysis device.

Embodiment 54: An analysis device according to any of the preceding embodiments with reference to the device, wherein the demodulation device independently multiplies the detector signal by the modulation frequencies and filters the results by using low-pass filters. An analysis device for determining a concentration of at least one analyte in a body fluid, provided to include.

Embodiment 55: The analysis device according to the preceding embodiment, wherein the demodulation device is provided such that the demodulation comprises filtering the detector signal by using at least one band pass filter prior to multiplying the detector signal by the modulation frequencies. , An assay device for determining the concentration of at least one analyte in a body fluid.

Embodiment 56: An analysis device according to the preceding embodiment, wherein the band pass filter is adjustable. An analysis device for determining a concentration of at least one analyte in a body fluid.

Embodiment 57: an analysis system for determining a concentration of at least one analyte in a bodily fluid, wherein the analysis system comprises an analysis device according to any of the preceding device embodiments, wherein the analysis system further comprises at least one test carrier. An assay system for determining the concentration of at least one analyte in a body fluid comprising.

Embodiment 58: An analysis system according to the preceding embodiment, wherein the test carrier is selected from the group consisting of a test strip, a test tape, a test disc, and an integrated test carrier having at least one test chemical and at least one lancet element. An analysis system for determining the concentration of at least one analyte in a body fluid.

Embodiment 59: An analysis system according to any of the two preceding embodiments, wherein the test carrier comprises at least one substrate and at least one test chemical applied to the substrate, wherein the test chemical is the analyte to be detected. An assay system for determining the concentration of at least one analyte in a bodily fluid, adapted to perform at least one detection reaction when present and to change at least one optically detectable property due to the detection reaction.

Further optional features and embodiments of the invention will be disclosed in more detail in a later description of specific embodiments of the invention, preferably together with the dependent claims. Here, each of the optional features may be realized in an isolated manner, as well as in any arbitrary feasible combination, as will be appreciated by those skilled in the art. The scope of the invention is not limited by the specific embodiments. The embodiments are schematically shown in the figures. Here, the same reference numerals in the drawings refer to the same or functionally comparable elements.
In the drawings:
1 shows a schematic diagram of an exemplary embodiment of a proposed analysis system including an exemplary embodiment of a proposed analysis device and a test carrier; And
2 shows an exemplary embodiment of the signal of the detector.

In FIG. 1, a schematic diagram of an analysis system 110 for determining the concentration of at least one analyte in body fluid 112 is shown. The analysis system 110 includes an analysis device 114. The analysis system 110 also includes a test carrier 116, which, in this exemplary embodiment, may be embodied as a test strip. The test carrier 116 may include at least one substrate 118 and at least one test chemical 120 that may be applied to and/or incorporated into the substrate 118. . The test chemical 120 is provided to change at least one optically detectable property due to the detection reaction. The analysis device 114 includes a container 122 into which the test carrier 116 may be inserted.

The analysis device 114 may comprise at least one, preferably two or more modulation devices 124. Each of the modulation devices 124 may include at least one signal source 125. Each of the signal sources 125 may generate a different set of control signals, such as three or more control signals, having different modulation frequencies, such as having three or more different modulation frequencies.

In the embodiment shown in FIG. 1, the three modulation frequencies of the three control signals of the first modulation device 124 are represented by _{f 1a} , f _1b , and f _{1c, while} The three modulation frequencies of the three control signals are denoted by _{f 2a} , f _2b , and f _2c.

For further reference, devices and processes relating to a first set of frequencies may be referred to as a first channel, while devices, frequencies, and processes relating to a second set of frequencies will be referred to as a second channel. May be. The analysis device may further comprise two or more mixer units 126. For potential details of mixer units 126, reference may be made to EP 1 912 058 B1. Control signals generated by the first channel may be transmitted to the mixer unit 126a, and the control signal of the second channel may be transmitted to another mixer unit 126b. For both of the channels, the control signal may be generated by mixing the three control signals in the mixer unit 126.

The analysis device 114 includes at least one light source 127. As shown in FIG. 1, the light source 127 includes a first light source 128 and a second light source 130. The first light source 128 may be controlled by the control signal of the first channel, while the second light source 130 may be controlled by the control signal of the second channel. The test carrier 116 is illuminated by light emitted from the first light source 128 and the second light source 130. The test carrier 116 carries the light detected by the detector 132. The detector 132 may convert the optical signals into an electronic signal, hereinafter also referred to as a detector signal and referred to as a symbol by reference numeral 133 in FIG. 1. In this embodiment, the detector signal 133 is modulated by six modulation frequencies.

The analysis device 114 further comprises at least one demodulation device 134. A demodulation device 134 is provided for demodulating the signal of the detector 132. As shown in FIG. 1, demodulation device 134 may include three multiplication devices 136 and three low pass filters 138 for each of the two channels. In each of the multiplication devices 136, the detector signal may be multiplied with one of the modulation frequencies or may be mixed with one of the modulation frequencies, where each of the modulation frequencies is used only once. In each of the low-pass filters 138, the result of the previous multiplication may be filtered. Accordingly, at the output ports of each of the low-pass filters 138, demodulated detector signals, symbolized by reference numerals 139 in FIG. 1, may be provided. In an alternative nomenclature, each of the outputs providing demodulated detector signals 139 may form a channel of demodulation device 134.

As shown in FIG. 1, one of the multiplication devices 136 can be realized as a lock-in amplifier 140 in combination with one of the low-pass filters 138. Demodulation device 134 may further include a band pass filter 142 configured to filter the detector signal prior to passing the detector signal to lock-in amplifiers 140.

The analysis device 114 further comprises a fault detection device 144, configured to, for example, perform fault detection for each of the two channels. The error detection device 144 may be provided to perform the comparison procedure symbolized by reference numeral 146 in FIG. 1. During the comparison procedure 146, the demodulated detector signals 139 denoted as _{val (f 1a , b, c} ) and val (f _{2a , b, c) may be compared.} For example, in the first channel, _{when one of the demodulated detector signals of val (f 1a} ), val (f _1b ), and val (f _1c ) differs from other demodulated detector signals by exceeding a certain threshold, , The demodulated detector signal of each acceptable frequency may be rejected from further evaluation. As long as the two demodulated detector signals are identical at least within a predetermined or adjustable tolerance, an average value may be calculated from these demodulated detector signals for further evaluation. If all of the demodulated detector signals differ from each other by more than a predetermined or adjustable threshold, an error value may be issued, and/or the photometric measurement may be restarted with a new set of frequencies. The comparison process 146 may be performed with a data processing device and/or computer.

Error detection may be performed as online error detection. Accordingly, error detection may be performed repeatedly or permanently during the photometric measurement. Further, error detection may be performed before applying a sample of bodily fluid 112 to the test carrier 116, for example during determination of the dry empty value.

In addition, the analysis device 114 of FIG. 1 includes an evaluation unit 148 provided for determining the concentration of an analyte by evaluating the input of the error detection device 144 of each of the two channels. In the evaluation unit 148, the concentrations of the analytes determined in the two channels may be compared, and an error value may be issued when the determined values are different from each other by exceeding a certain threshold. For details of evaluation unit 148, reference may be made to the disclosure given above and/or to the prior art documents cited above.

In FIG. 2, an exemplary embodiment of the signal 133 of the detector 132 is shown. The dependence of the frequency f [Hz] on the attenuation a [dB] is shown. Signal 133 may include six modulation frequencies 150-160. The signal 133 may be determined by the detector 132 before demodulation by the demodulation device 134 and before determining the measurement result by the evaluation unit 148. Signal 133 may not include disturbances. The six modulation frequencies 150-160 used may have the same strength. In addition, the signal-to-noise ratio SNR of signal 133 is shown. The SNR may be large enough to distinguish each of the modulation frequencies 150-160 from the noise of the detector 132.

List of reference numbers
110 analysis system
112 bodily fluids
114 Analysis device
116 test carrier
118 substrate
120 test chemicals
122 containers
124 modulation devices
125 signal source
126 mixer unit
127 light source
128 first light source
130 second light source
132 detector
133 detector signal
134 demodulation device
136 Multiplication Device
138 low-pass filter
139 demodulated detector signals
140 lock-in amplifier
142 band pass filter
144 error detection device
146 Comparison Procedure
148 Evaluation Unit
150 modulation frequency
152 modulation frequency
154 modulation frequency
156 modulation frequency
158 modulation frequency
160 modulation frequency

Claims (18)

A method for determining the concentration of at least one analyte in a bodily fluid sample, comprising:
a) applying the bodily fluid sample to a test carrier;
b) illuminating the test carrier with at least one light source, wherein the at least one light source is at least one first light source modulated with at least two modulation frequencies and the at least two modulations by which the first light source is modulated Illuminating the test carrier comprising at least one second light source modulated with at least two modulation frequencies different from frequencies, the at least one light source being modulated by using at least two different modulation frequencies;
c) receiving light carried by the test carrier with at least one detector;
d) determining an analyte concentration by evaluating at least one detector signal generated by the at least one detector, wherein the at least one detector signal comprises the at least two detector signals to generate at least two demodulated detector signals. Determining the analyte concentration, demodulated with different modulation frequencies, each demodulated detector signal corresponding to one of the at least two different modulation frequencies; And
e) detecting an error by comparing the at least two demodulated detector signals. The method of claim 1,
The method for determining the concentration of at least one analyte in a bodily fluid sample, wherein step e) is an online error detection performed permanently or repeatedly. The method of claim 1,
The method for determining at least one analyte concentration in a bodily fluid sample, wherein the at least one light source is modulated by using at least three modulation frequencies. The method of claim 1,
Wherein step e) further comprises detecting faulty demodulated detector signals. The method of claim 4,
Wherein step e) further comprises rejecting erroneous demodulated detector signals, and using only non-faulty demodulated detector signals to determine the at least one analyte concentration in the bodily fluid sample. , A method for determining the concentration of at least one analyte in a bodily fluid sample. The method of claim 5,
At least one erroneous demodulated detector signal is used to determine the at least one analyte concentration, and the degree of faultiness is accounted for in a method for determining at least one analyte concentration in a bodily fluid sample . delete The method of claim 1,
At least two demodulated detector signals are generated for the modulation frequencies that cause the first light source to be modulated, and at least two demodulated detector signals are generated for the modulation frequencies that cause the second light source to be modulated, A method for determining the concentration of at least one analyte in a bodily fluid sample. The method of claim 8,
The step e) comprises the at least two demodulated detector signals for the at least two modulation frequencies causing the first light source to be modulated, and the at least two for the modulation frequencies causing the second light source to be modulated. A method for determining at least one analyte concentration in a bodily fluid sample, performed on both of the four demodulated detector signals. The method of claim 1,
The method for determining the concentration of at least one analyte in a bodily fluid sample, wherein step e) is performed at least once before step a). The method of claim 10,
Further comprising determining at least one dry empty value by evaluating the at least one detector signal generated by the at least one detector prior to applying the bodily fluid sample to the test carrier, A method for determining the concentration of at least one analyte in a bodily fluid sample. The method of claim 1,
The step of verifying the location of at least one of the test carrier, further comprising:
i) inserting the test carrier into an analysis device;
ii) illuminating the test carrier by the at least one light source;
iii) receiving the light carried by the test carrier by using the at least one detector; And
iv) determining at least one position of the test carrier in the analysis device by evaluating at least one detector signal generated by the at least one detector, wherein the at least one position is a location or orientation of the test carrier. Determining at least one location of the test carrier, comprising at least one of
A method for determining the concentration of at least one analyte in a bodily fluid sample comprising a. The method of claim 1,
Further comprising detecting at least one ambient light error, wherein detecting the ambient light error comprises:
I. receiving ambient light by using the at least one detector;
II. Evaluating at least one detector signal generated by the at least one detector; And
III. Performing ambient light error detection by comparing the at least one detector signal generated by the at least one detector with the at least two different modulation frequencies
A method for determining the concentration of at least one analyte in a bodily fluid sample comprising a. The method of claim 1,
The demodulation comprises independently multiplying the at least one detector signal by the at least two modulation frequencies and filtering the results by using low-pass filters to determine at least one analyte concentration in a bodily fluid sample. Way to do it. The method of claim 14,
The demodulation comprises filtering the at least one detector signal by using at least one band pass filter prior to multiplying the at least one detector signal by the at least two different modulation frequencies. A method for determining the concentration of at least one analyte. The method of claim 1,
-Inserting the test carrier into an analysis device;
-Initiating the error detection; And
-Acquiring the dry empty value
A method for determining the concentration of at least one analyte in a bodily fluid sample, further comprising at least one of. An analytical device for determining the concentration of at least one analyte in a body fluid, comprising:
The analysis device:
At least one container for receiving at least one test carrier, wherein at least one bodily fluid is applicable to the at least one test carrier;
At least one light source configured to illuminate the at least one test carrier, wherein the at least one light source is a first light source configured to be modulated by at least two modulation frequencies and the at least two modulations to which the first light source is modulated The at least one light source comprising at least one second light source configured to be modulated by at least two modulation frequencies different from the frequencies;
At least one detector configured to receive light carried by the at least one test carrier;
At least one evaluation unit configured to determine the at least one analyte concentration by evaluating at least one detector signal generated by the at least one detector;
At least one modulation device configured to modulate the at least one light source by using at least two different modulation frequencies;
At least one demodulation device configured to demodulate the at least one detector signal to the at least two modulation frequencies to produce at least two demodulated detector signals, each demodulated detector signal being the at least two modulation frequencies The at least one demodulation device corresponding to one of; And
At least one error detection device configured to perform fault detection based on a comparison of the at least two demodulated detector signals
Containing, analysis device. An analysis system for determining the concentration of at least one analyte in a sample of bodily fluid, comprising:
The analysis system:
The analysis device according to claim 17; And
At least one test carrier
Containing, analysis system.

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